Hi there!
I would like to offer my services for this task. I have been developing Shopify stores for more than 3 years now. Currently I work for one of the top Shopify developing companies in Europe and in free time I offer my services on Freelancer. I'am a new user on Freelancer, but if you wish to see any of my previous jobs, please feel free to ask. My previous clients include well known names such as Vanilia, Mr Marvis, Nike, Ti Sento Milano, Bakker, Veloretti and many more.
Before I can provide you with an estimate, I would require a store url to run all required diagnsotics and determinate what kind of implements are required and how long would it take.
If you are interested in my services, please feel free to get in touch with me and we can arrange a Skype or Google hangouts meeting to go trough your requirements.
I look forward for your reply.
Best luck with your project!
Kind regards,
Aivis